On May 4, 1959, the first major addition to the University of Washington Health Sciences Building, an eight-story, $10 million structure was opened. The hospital, which was dedicated in 1949, included 291 beds, a nursery, and extensive research facilities..

Renamed the Magnuson Health Sciences Center in 1978 in honor of Senator Warren G. Magnuson, the complex consists of more than 20 wings, with nearly 5.8 million square feet of floor space — making it one of the largest buildings in the U.S.